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Protection of Fruits, Vegetables, and other 

Food Products from Injury by Heat 

or Cold during Transportation. 



The following various opinions as to the temperatures that are 
injurious to perishable articles, under different conditions, have been 
received by the Weather Bureau from the shippers throughout the 
country in reply to a circular letter on the subject, and are published 
for the benefit of all concerned : 

In the transportation of perishable freight there are three primal 
objects to be attained : 

1. The protection of the shipment from frost or excessive cold. 

2. The protection of the same from excessive heat. 

3. The circulation of air through the car, so as to carry off the 
gases generated by this class of freight. 

The temperatures at which perishable goods would be damaged 
vary greatly with different commodities, their condition when 
shipped, how long they may be in transit, whether they are kept con- 
tinually in motion, etc. 

In transporting perishable articles injury can occur from long 
exposure to a temperature but little below 32°, or from a shorter ex- 
posure to a greater cold, so that the duration as well as the intensity 
of the cold must be considered. 

Oranges on the trees will stand a temperature of 26° for an hour or 
so, but if exposed to that temperature for four hours will freeze in- 
side. 

Oranges slightly frozen, when placed in a cool room and thawed out 
gradually, are sweetened, and may be considered by some people as 
improved, but when frozen solid and thawed they have a " sickish " 
sweet flavor. 

When oranges have been frozen they can be thawed without injury 
by putting them in cold water or tight barrels immediately after 
arrival, and allowing them to thaw out gradually. 

In shipping perishable goods a great deal depends on the condition 
of the car ; if the car is tight and in good shape apples and potatoes 
will stand a zero temperature. 

Irish potatoes in a store, with a cellar under them, will stand a 
temperature of 10°, and without a cellar a zero temperature will not 
hurt them. 

Articles shipped from the North to the South during winter should 
be in a perfectly dry condition. 



As a rule, truckers will not haul vegetal^les to the cars for ship- 
ment when the temperature reaches 20°, or lower, and in no case when 
it is near 32°, if raining or snowing. 

The degree of cold to which perishable goods may be subjected 
without injury depends on the time the shipment will be on the road, 
also whether it will be unloaded immediately upon arriving at its 
destination or allowed to stand twenty-four hours, also direction of 
shipment, whether toward a cold area or away from it. 

Shucked oysters shipped in their own liquor in tight barrels will 
not spoil if frozen while in transit. Thick or fat clams or oysters 
will not freeze as readily as lean ones, as the latter contain much 
more water. Oysters will not freeze as readily as clams. It is safer 
when oysters or clams in the shell are frozen to thaw them out gradu- 
ally, in the original package, in a cool place. Clams and oysters in 
transit through a snowstorm will not freeze as readily as when the 
weather is fair and a stiff wind prevails. 

Canned tomatoes when frozen become stringy, canned fish soft and 
mushy, lemons black and spotted, olives soft and rancid, pickles soft 
and unsalable. 

The temperature to which lemons, oranges, and bananas may be 
exposed without damage varies in different localities, and' the different 
temperatures at those points seem to depend a great deal on the 
moisture. 

Shippers and agents concur in the statement that danger in trans- 
portation by freezing has been practically eliminated in the shipment 
of produce by modern methods ; the lined car suffices in spring and 
autumn and usually during the winter, while in extreme weather the 
Eastman heater car is used. The temperature of the produce when 
put into the car is quite a factor to be observed. It is also claimed 
that a car load of produce, like potatoes, will stand a lower tempera- 
ture when the car is in motion than when at rest. 

Fruit should not be subjected to a temperature lower than 85° or 
higher than 60°. Wines should not be subjected to a temperature 
lower than 20° or higher than 72°. 

In ordinary freight cars perishable goods can be shipped with 
safety with the outside temperature at 20°, and in refrigerator cars 
at 10°. 

If perishable goods are put in a box car upon a cold day, and they 
have radiated considerable heat before being shipped, they will not 
be able to withstand as low a temperature, and here is where the differ- 
ence as to the degrees of temperature mainly applies. 

Fruit wrapped in heavy brown paper will stand 15° more cold than 
if not wrapped. 

In what are known as refrigerator cars, perishable goods may be 
safely shipped with a temperature outside of from zero to 10° below ; 



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the car first being lieated, and when arriving at the end of journey 
the goods being taken immediately into a warm place without being 
carted any great distance. 

It is not safe to ship olives in any car, unless heated artificially, 
when the temperature is below 25°. 

The better class of refrigerator cars, such as used by the California 
Fruit Company, will carry all perishable goods safely through tem- 
perature as low as 20° below zero, provided they are not subjected to 
such temperatures longer than three or four days at a time, while 
with the ordinary refrigerator cars temperatures of zero are considered 
dangerous especially if the goods they contain be of the most perish- 
able kind. 

Beer can be shipped at an outside temperature of 10° if placed in a 
refrigerator car and the kegs packed in hay or sawdust and fresh 
stable manure, the packing being 6 inches or more all around. 

Eastern grapes bear low temperatures better than California or 
Malaga. 

While a temperature as low as freezing (32°) will not injure pota- 
toes for eating purposes, yet they will fail to sprout in the spring. 

Roses and cut flowers will not be injured unless the temperature 
falls to 32°. Roses need as low a temperature as possible without 
freezing, because they are shipped as buds and would develop if the 
temperature were high. 

It appears to be generally conceded that goods, when free from 
undue dampness, that is those classed as dry, will stand a much 
lower degree of temperature without injury. 

METHODS EMPLOYED BY SHIPPERS OF PERISHABLE 
GOODS TO PROTECT THE ARTICLES FROM DAMAGE 
BY FREEZING, BOTH BY PACKING AND SHIPPING, IN 
CERTAIN KINDS OF CARS. 

Many of the precautions in packing that may keep out the cold 
would also keep in the heat, and there is really more danger, in some 
instances, from heating, by process of decomposition, than from 
cold. 

In shipping car loads of bananas a man is usually sent in charge 
to open and close the ventilators. 

Precautions taken in shipping are papering, packing in straw or 
sawdust, boxing, barreling with paper lining, shipping in paper-lined 
cars, refrigerator cars, and cars heated by steam, stoves, and sala- 
manders. 

During cold weather oysters and clams should be shipped in tight 
barrels lined with paper. 

In shipping perishable goods it is well to cover them with two 
sheets of heavy paper, weighing about 1^ pounds each. 



Bananas should be put in a paper bag and a heavy canvas bag and 
then covered with salt hay, but when put in automatic heaters the 
fruit is packed only in salt hay. 

In packing articles in a car for shipment, potatoes are packed in 
straw, bulkheaded back, center of car left empty, and car filled as 
high as double lining, while some of the cars have a double bottom. 

French mustard and aqua ammonia are packed in sawdust and 
securely boxed, being careful to allow the sawdust to form a layer 
between the articles and the side of the box. 

Eggs are packed in crates with separate pasteboard divisions with 
a layer and a cover of oat chaff. 

Quinces, apples, onions, and pears are packed in barrels, each layer 
of barrels covered and resting on straw. 

Tomatoes, lemons, and oranges are packed in crates, each layer of 
crates in the car is covered and rests upon straw, usually bulkheaded 
Ijack from the door and car full. 

Shrubs and fruit trees are laid on straw, covered with it on all 
sides, and car packed full. 

Flowers are packed in moss and car filled. 

Flowers, shrubs, and trees should have their roots carefully packed 
in straw and the roots placed together in two or three piles, so as to 
protect them ; if the roots are killed, they are of a uniform black ; if 
only injured by frost, the root is pinkish in color just below the outer 
covering ; and if sound, they are of a uniform white. Even if of a 
dark pink color, no damage need result, if the frost is gradually 
thawed out by the trees being left in the closed car for four or five 
days, or else put the roots well down in the soil in a horizontal posi- 
tion and thaw out gradually. 

Extra precautions are taken with trees, etc., when passing over 
mountains, and no shipments are made when the temperature is 
likely to be zero any where in the higher regions. 

Cars containing perishable goods are sometimes, when a north 
wind is blowing on the prairie, covered with canvas on the north side. 

Oranges shipped from Florida to points as far north as Minnesota 
are started in ventilator cars, which arc changed at Nashville to air- 
tight refrigerator cars, the ventilators of which are kept open, pro- 
vided the temperature remains above 32°, until arrival at St. Louis, 
from which point the ventilators are closed and the cars made air 
tight. 

In winter time refrigerator cars are used without ice in forwarding 
goods from the Pacific coast, and in passing through cold belts or 
stretches of country the hatches are closed, and the cars being lined 
and with padded doors, the shipment is protected against the outside 
temperature; but in passing through warmer climates the ventilators 



of the cars are opened in order to prevent the perishable goods from 
heating and decaying. 

Manure is largely used to protect perishable goods, the bottom of 
the car being thickly covered with it, and in some cases it is put on 
top of the goods. 

To protect goods shipped in an ordinary car, the sides of the car 
should be protected by heavy paper tacked to the wall and by the ad- 
dition of an inner board wall a few inches distant from the other one. 
A car thus equipped and packed with produce surrounded by straw 
will retain sufficient heat to prevent injury for twenty-four hours, the 
average air temperature of all parts of the car being at least 12° 
higher than that of the outside air. 

In shipping potatoes, when the temperature is 12°, or more, below 
freezing, the rule is to line the barrels with thick paper, and at ex- 
tremely low temperatures, as a matter of extra precaution, the barrels 
are covered over the outside with the same kind of paper, which is 
considered the best known protection from frost. 

All products sent loose in a car are packed in straw on all sides, 
paying particular attention to the packing around doors, and to see 
that the car is full. 

Certain classes of goods, embracing peaches, melons, and grapes, 
are taken by some railroads in no other way. 

To transport potatoes, place an extra floor and sides in the car, 
leaving an air space of from 4 to 6 inches, then place a stove in the 
center. 

Oranges loaded in ventilated or common cars should be transferred 
to refrigerator cars when the temperature reaches 10° above zero. 
When oranges are transferred to refrigerator cars, or if loaded in ven- 
tilated refrigerators, and the ventilation is closed, the car must be 
iced sufficiently to prevent heating. 

Ventilators on cars containing bananas, lemons, and other delicate 
fruits must be closed at a temperature of 40°. 

Cars are warmed by steam from the locomotive when in motion, 
and by stoves when steam is not available. 

Cars after being loaded are carefully inspected as to temperature 
within, their destination considered, and if the weather is exceedingly 
cold, or is liable to be, the car is often accompanied by an attendant ; 
otherwise it is inspected from time to time on the road. 

Oranges in transit, with a falling temperature, the ventilators should 
be closed when the thermometer reaches 20°, and with a rising tem- 
perature the ventilators should be opened when 28° is reached. For 
lemons the minimum is 35° for opening and closing the ventilators, 
and for bananas, 45° for opening or closing. 

Lined cars, that is, cars lined with tongued and grooved boards on 
the sides and ends, leaving an air si^ace of about 4 inches, are con- 



6 

sidered the best by heavy shippers of potatoes, as they can be heated 
by an ordinary stove, and will stand a temperature outside of 20° be- 
low zero, when a man is in charge to keep up the fires. 

THE RELATION BETWEEN THE OUTSIDE AIR TEMPERA- 
TURE AND THE TEMPERATURE WITHIN AN ORDINARY 
FREIGHT CAR AND CARS SPECIALLY ADAPTED TO THE 
TRANSPORTATION OF PERISHABLE GOODS. 

From six observations taken at intervals of ten minutes it was 
found that on a warm day, when the mean of the six readings out- 
side was 68°, it was 66° on the inside of an ordinary freight car, and 
63° inside of an uniced refrigerator car ; on a cold day the mean of 
six observations was 33° outside and 35° inside of an ordinary car, 
and 38° inside of a refrigerator car ; the car was stationary. 

The difference of temperature inside and outside of a car is from 
5° to 15°, depending whether it is an ordinary freight car or refriger- 
ator car, whether lined or not, and whether there are strong winds. 

The difference of temperature in a box car and the outside air is 
from 3° to 6°, according to how tight the car is built. 

Refrigerator cars, immediately upon being opened, showed 31.8° on 
coldest day to 40° on warmest. An Eastman heater showed 75° at 
5° a. m., while the temperature of air was 55° ; fire was put out and 
at 9.30 a. m. the temperature was 60°. 

The relation between air temperature and temperature within a car 
varies somewhat. Ordinarily a temperature of about 20° outside cor- 
responds to a freezing temperature (32°) within the car. The rela- 
tion between the two is in proportion to the speed of the car. With 
a car standing still the difference is very slight. 

Refrigerator cars are the most desirable for shipping, as the differ- 
ence in temperature within such cars and the outside air amounts to 
from 15° to 30°, the sides being filled in with sawdust and the cars 
provided with heating apparatus, which permits of shipments ))eing 
made in them, however cold the weather might be. For ordinary win- 
ter weather, the temperature ranging from 10° to 30° above zero, 
refrigerator cars may ))e used for shipment to any distance without 
being heated. 

Freight from the Pacific coast to the Mississippi Valley, or even to 
the Atlantic coast has to pass through almost every variety of cli- 
mate at any time of the year. It is therefore obvious that at one 
time the temperature inside of the car is materially above the out- 
side temperature, while perhajis a few hours later, it is below. 

The difference between the air temperature and that of the inside 
of an ordinary car depends upon what the car is loaded with ; if ap- 
ples, the difference will be from 10° to 12°, if jjotatoes from 15° to 
18°, warmer than when unloaded. 



The lowest and highest temperatures to which perishable goods may be subjected to 
without injury under the conditions stated. 



Perishable goods. 



Apples, in bbls 

Apples, loose 

Apricots, baskets 

Aqua ammonia, bbls 

Bananas 

Beer or ale, kegs 

Bluing 

Cabbage in crates 

Cantaloupes 

Celery 

Cheese 

Cider 

Clams 

Cranberries 

Cocoanut 

Drugs (non-alcoholic) .. 
Eggs, barreled or crated 
Extracts (flavoring) .... 

Fish, canned 

Flowers 

Grapes 

Grape fruit 

Groceries, liquid 

Ink 

Lemons, boxed 

Lobsters 

Mandarins 

Medicines, patent 

Milk 

Mucilage 

Mustard, French 

Olives in bulk 

Olives in glass 

Oranges, boxed 

Onions, boxes 

Oysters in shell, bbls... 

Oysters, shucked 

Paste 

Peaches, fresh, baskets. 

Peaches, canned 

Pickles in bulk 

Pickles in glass 

Pineapples 

Plums 

Potatoes, Irish, bbls .... 

Potatoes, sweet 

Shrubs, roses or trees . . 

Strawberries 

Tangerines 

Tomatoes, fresh 

Tomatoes, canned 

Vegetables 

Vinegar, bbls 

Waters, mineral 

Wines, light 

Yeast 



jO wes t outside 
temperature. 



-ti^ 



Zero. 

— ID 

Zero. 



— 10 
— 10 

Zero. 
Zero. 
Zero. 
Zero. 
Zero. 

—ID 

— 10 

Zero. 
Zero. 
Zero. 

—10 
10 

Zero. 
Zero. 
Zero. 
Zero. 
Zero. 

— 10 

Zero. 
Zero. 
Zero. 
Zero. 

— 10 

Zero. 

10 
10 

Zero. 

—10 
— 10 

Zero. 
Zero. 

10 
10 



Zero. 



— 5 

10 

— 10 

Zero. 
Zero. 
Zero. 



75 



75 



8o 



65 



Remark.s. 



In barrels covered with straw. 
Packed in straw. 



In paper bags ; packed in salt hay. 
Packed in manure and shavings. 



In boxes. 



Packed in moss. 
Packed in cork. 



In boxes. 

Packed in sawdust. 



In barrels. 



Do. 
Do. 



Do. 



In boxes with paper. 

In barrels. 

In canvas or sacking. 

In boxes. 

Do. 



> 



Mark Wc^arrington, 

Chief of Bureau. 



U. S. 



Department of Agriculture, 
Weather Bureau, 

Washington, D. C, August 22, 



1894. 



LIBRARY OF CONGRESS 



000 929 175 1 • 



